1. Field of the Invention
This invention relates to apparatus and an associated method for energizing a remote station through energy transmitted in space and, more specifically, it relates to such a system wherein data with respect to an object of interest may be obtained by the remote station and transmitted to the base station upon interrogation by the base station.
2. Description of the Prior Art
It has long been known in various applications to monitor conditions of a physical system or a patient and provide information in the nature of real-time readouts of certain conditions. Such systems typically have been connected by a suitable wire to a source of electricity at the desired voltage such as line current or batteries.
It has also been known to provide such systems in the medical environment in respect of monitoring characteristics such as patient respiration, heart beat, electrocardiograms and temperature, for example. See, generally, U.S. Pat. Nos. 4,129,125; 4,308,870; 4,443,730; 4,889,131; and 5,335,551.
It has also been known in the medical environment to monitor physiological parameters by employing sensors, a battery powered system, and digital processing means to effect comparison between the measured conditions and stored values and displaying the results. See U.S. Pat. No. 4,356,825.
U.S. Pat. Nos. 5,230,342 and 5,586,555 disclose blood pressure monitors employing a pressurizable pressure transducing bladder with particular emphasis on measuring blood pressure in a supraorbital artery.
U.S. Pat. No. 4,576,179 discloses the use of a chest motion transducer and associated heart rate monitoring apparatus. Cooperating electronics are provided. Alarm means may be triggered under appropriate conditions of the individual being monitored or an indication that the battery voltage has fallen below a preset level. There is an allusion to making provision for short range radio transmission of the signals to remote monitoring stations. See also U.S. Pat. No. 5,022,402.
U.S. Pat. No. 4,494,553 discloses a battery powered respiratory and cardiac monitor wherein a pair of inductance coils are employed along with VHF/FM transmission of signals.
It has been known to suggest the use of a wireless communication link between a base station and transponders in a radio frequency identification system employing modulated back-scattered waves separate attachment of an antenna to a tag integrated current is disclosed. See Rao, an overview of Bulk Scattered Radio Frequency Identification System (RFID) I EEE (1999).
It has been suggested to employ a silicon chip in a transponder having a change pump on voltage doubler current. Hornby, RFID Solutions for the express parcel and airline baggage industry, Texas Instruments, Limited (Oct. 7, 1999).
In spite of the foregoing known systems, there remains a need for a remote unit usable in various environments and at various distances from the base station which remote unit will be adapted to be remotely energized so as not to require hard wired systems or batteries on the remote unit. There is also lacking such systems wherein the remote unit may be miniaturized so as to have numerous potential uses.
The present invention has met the above-described needs. In the present invention, apparatus for remote interaction with an object of interest includes a remote station for obtaining information from the object of interest and a base station for transmitting energy in space to the remote station and communicating with the remote station. The remote station has conversion means for energizing the remote station by employing the transmitted energy. The base station may transmit the energy as RF power, light, acoustic, magnetic, or in other suitable forms of space transmitted or xe2x80x9cradiantxe2x80x9d energy.
A power supply is provided for energizing the base station with first antenna means being provided on the base station and second antenna means being provided on the remote station. Sensor means or other information providing means permits the remote station when energized by the base station to transmit information to the base station regarding the object of interest and certain conditions of the remote station. This may be done in real-time. The remote station may be provided with a plurality of transponders each of which may be interrogated by the base station sequentially to provide separate informational packets.
A method of the present invention provides for remote interaction with an object of interest, including providing the remote station and a base station operatively associated therewith, with energy being transmitted in space from the base station to the remote station, and the energy so transmitted being converted by the remote station into electrical power to energize the remote station.
The remote station may be provided with a plurality of transponders each of which will be a source of different information from the other.
The system eliminates the need for batteries on the remote station or the use of hard wired systems.
The invention also provides systems which employ voltage or power enhancing units on the remote station. When employed on electronic chips, antennas having a greater effective area than physical area may be employed advantageously.
The system is adapted for use on system on a chip (SOC) miniaturized unit.
It is object of the present invention to provide a remote station which is adapted to provide information to a base station when interrogation by the base station is initiated.
It is another object of the present invention to provide such a system wherein the remote station is not required to contain an energy storage device, such as a battery, or to be part of a hard wired or printed circuit system.
It is a further object of the present invention to provide such a system wherein energy transmitted in space, such as RF power or light, will be converted into DC power or AC power on the remote station to operate the remote station.
It is a further object of the present invention to provide such a system wherein RF power may be employed to initiate operation of the remote station regardless of whether light is present.
It is a further object of the present invention to provide such a remote station which will transmit dynamic real-time measurements to a base station.
It is another object of the present invention to provide such a system wherein the remote station may be miniaturized and does not require frequent maintenance.
It is another object of the present invention to provide such systems wherein enhanced energy harvesting on a remote station is provided.
It is a further object of the present invention to provide such a system wherein use on miniaturized Systems on a Chip (SOC) is facilitated.
It is yet another object of the present invention to provide such systems wherein the effective antenna area exceeds the physical antenna area.
It is a further object of the present invention to provide such systems which may be employed effectively in Radio Frequency IDentification (RFID) devices.
It is a further object of the present invention to provide such a system wherein the remote station may have a plurality of passive intelligent transponders.
These and other objects of the invention will be more fully understood from the following description of the invention on reference to the accompanying drawings.